Injection molding machine with vertical plasticizing unit

ABSTRACT

An injection molding machine includes a clamping unit constructed for support of at least two molding tools to provide at least two different cavities. A first plasticizing unit is provided for charging one of the cavities in one of the molding tools, and a second plasticizing unit is provided for charging the other one of the cavities in the other one of the molding tools. The second plasticizing unit is hereby attached to a mounting in a substantially vertical orientation. The mounting may be mounted on one of the platens of the injection molding machine or on a frame which extends above the clamping unit.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a division of prior filed U.S. application Ser. No.11/748,535, filed May 15, 2007, now U.S. Pat. No. 7,484,948, thepriority of which is hereby claimed under 35 U.S.C. §120, which in turnis a continuation of prior filed copending PCT International applicationno. PCT/EP2005/055920, filed Nov. 11, 2005, which designated the UnitedStates and has been published but not in English as InternationalPublication No. WO 2006/056539 A1 and on which priority is claimed under35 U.S.C. §120 and which claims the priority of German PatentApplication, Serial No. 10 2004 057 164.3, filed Nov. 26, 2004, pursuantto 35 U.S.C. 119(a)-(d), the contents of which are incorporated hereinby reference in its entirety as if fully set forth herein.

BACKGROUND OF THE INVENTION

The present invention relates, in general, to the field of injectionmolding machines.

Nothing in the following discussion of the state of the art is to beconstrued as an admission of prior art.

A typical injection molding machine includes a clamping unit for supportof at least two molding tools to provide at least two different cavitiesfor production of multicomponent products. The clamping unit may beconstructed as a stack mold or include an intermediate plate in the formof a sliding plate or a swivel plate. As a result, the overall injectionmolding machine is of drawn-out construction whose footprint issubstantial. Examples of such injection molding machines include GermanOffenlegungsschriften DE 199 37 200 and DE 101 38 087.

It would therefore be desirable and advantageous to provide an improvedinjection molding machine to obviate prior art shortcomings

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an injection moldingmachine includes a clamping unit constructed for support of at least twomolding tools to provide at least two different cavities, a firstplasticizing unit for charging one of the cavities in one of the moldingtools, a second plasticizing unit for charging the other one of thecavities in the other one of the molding tools, a mounting forattachment of the second plasticizing unit in a substantially verticalorientation, and at least two platens, wherein the mounting is securedto one of the platens.

According to another aspect of the present invention, an injectionmolding machine includes a clamping unit constructed for support of atleast two molding tools to provide at least two different cavities, afirst plasticizing unit for charging one of the cavities in one of themolding tools, a second plasticizing unit for charging the other one ofthe cavities in the other one of the molding tools, a mounting forattachment of the second plasticizing unit in a substantially verticalorientation, and a frame disposed above the clamping unit, said mountingbeing secured to the frame.

The present invention resolves prior art problems by orienting one ofthe plasticizing units in a substantially vertical direction. In orderto be clear on this point, it is to be understood that the term“substantially vertical direction” includes a positioning of the oneplasticizing unit at an angle ranging from about 45° to 90°. In otherwords, the benefits of the invention can be realized even though theaxis of the plasticizing unit is not coincidental with the vertical butrather may be slanted up to an angle of about 45° in relation to thevertical.

The clamping unit may be constructed as a stack mold or include anintermediate plate. In the latter case, the intermediate plate ispositioned between the platens, with one of the molding tools beingdisposed between the intermediate plate and one of the platens, and theother one of the molding tools being disposed between the intermediateplate and the other one of the platens. The intermediate plate may beconstructed for movement in a linear direction and/or rotation. When theintermediate plate is constructed for rotation, the use of a swivelplate with clocked reversal becomes also possible.

According to another feature of the present invention, the mounting andthe second plasticizing unit can be constructed and positioned such thatthe plasticizing cylinder of the second plasticizing unit is arranged atan end face outside of the clamping unit, and a melt deflection devicemay be provided which is connected or connectable to the secondplasticizing unit for introduction of plastic melt, produced by thesecond plasticizing unit, into the associated one of the cavities.

According to another feature of the present invention, the frame forattachment of the mounting may be supported, at least in part, on amachine bed. It is, of course, also conceivable to support the frame onthe ground or any level surface on which the machine bed is placed. Theframe may envelope the entire clamping unit or only part thereof.

According to another feature of the present invention, the mounting maybe arranged on the frame for linear movement in opening and closingdirections of the clamping unit. As a result, the position of theinjection unit can be adjusted for different molding tools. Suitably,the frame supports two guide rails extending in parallel relationship ina longitudinal direction of the clamping unit for guiding the mountingin linear direction.

According to another feature of the present invention, the secondplasticizing unit may be arranged on the mounting for up and downmovements. As a result, the clamping unit can be retracted in relationto the molding tool as well as to the melt deflection device.

According to another feature of the present invention, one of theplatens may be fixed and the other one of the platens may be mobile. Itis, of course, also conceivable to construct both platens for mobility.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the present invention will be morereadily apparent upon reading the following description of currentlypreferred exemplified embodiments of the invention with reference to theaccompanying drawing, in which:

FIG. 1 is a schematic perspective view of a first embodiment of aninjection molding machine according to the present invention;

FIG. 2 is a schematic side view of the injection molding machine of FIG.1;

FIG. 3 is a schematic top view of the injection molding machine of FIG.1;

FIG. 4 is a schematic perspective view of a second embodiment of aninjection molding machine according to the present invention;

FIG. 5 is a schematic side view of the injection molding machine of FIG.4;

FIG. 6 is a sectional view of the injection molding machine of FIG. 4;and

FIG. 7 is a schematic top view of the injection molding machine of FIG.4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The depicted embodiments are to be understood as illustrative of theinvention and not as limiting in any way. It should also be understoodthat the figures are not necessarily to scale and that the embodimentsare sometimes illustrated by graphic symbols, phantom lines,diagrammatic representations and fragmentary views. In certaininstances, details which are not necessary for an understanding of thepresent invention or which render other details difficult to perceivemay have been omitted.

Turning now to the drawing, and in particular to FIG. 1, there is showna schematic perspective view of a first embodiment of an injectionmolding machine according to the present invention, including a clampingunit, generally designated by reference numeral 12 and mounted onto amachine bed 10. The injection molding machine includes an unillustratedfirst plasticizing unit which is positioned to the right of the clampingunit 12, and a second plasticizing unit, generally designated byreference numeral 32 and described in more detail hereinafter.

The clamping unit 12 includes a fixed platen 14 which is supported onthe machine bed 10 and a moving platen 16 which is movable back andforth along unlabeled rails on the machine bed 10. A swivel platearrangement with a swivel plate 22 and a drive for the swivel plate 22is arranged between the platens 14, 16, as clearly shown in FIG. 2.Although not shown in the drawings, the swivel plate 22 is also operatedby a separate drive for back-and-forth movement in opening and closingdirections of the clamping unit 12. The swivel plate 22, whichconstitutes an intermediate plate and has a generally block-shapedconfiguration, carries on all four sides of the block parts of a moldingtool 24. Through incremental turning of the swivel plate 22 by 90°, theindividual parts of the molding tools can be successively exchanged.

As shown in particular in FIGS. 2 and 3, the fixed platen 14 carries apart of a molding tool 26, and the moving platen 16 carries a part of amolding tool 27. In a closed position of the clamping unit 12, themolding tool parts 26, 27 form with the molding tool parts 24 a firstcavity (half-mold 24 and half mold 26) as well as a second cavity(half-mold 24 and half mold 27). The clamping pressure between bothplatens 14, 16 with in-between swivel platen 22 is realized in a mannerknown per se via tie bars and a hydraulic clamping unit for applying theclamping pressure.

As shown in FIGS. 1-3, the second plasticizing unit 32 is arranged onthe moving platen 16 in a vertical disposition. A mounting 30 is herebysecured to the top of the platen 16 for attachment of the plasticizingunit 32 which has a plasticizing cylinder 34 situated at the end face ofthe mounting outside of the clamping unit 12. In other words, theplasticizing cylinder 34 is situated outside of the moving platen 16 ata distance thereto.

A melt deflection device 36 is mounted to the moving platen 16 andextends there through to port into the cavity of the closed moldingtools 24, 27. The plasticizing cylinder 34 can be connected to the meltdeflection device 36 so that melt produced in the plasticizing unit 32can be introduced via the melt deflection device 36 into the cavity.Although not shown in the drawings, it will be understood by personsskilled in the art that the melt deflection device 36 may, of course,include further elements, such as a hot runner or a nozzle shut-offdevice.

The injection molding machine, described in FIGS. 1-3, is of compactconfiguration, even when used with a swivel plate type clamping unit forthe production of multicomponent products.

Referring now to FIG. 4, there is shown a schematic perspective view ofa second embodiment of an injection molding machine according to thepresent invention. In the following description, parts correspondingwith those in FIGS. 1-3 will be identified, where appropriate for theunderstanding of the invention, by corresponding reference numerals,each increased by “100”. The injection molding machine of FIG. 4includes a clamping unit 112 which is mounted onto a machine bed 110. Tothe right of the clamping unit is the first plasticizing unit 111 whichis positioned outside of the fixed platen 114. In addition to the fixedplaten 114, the clamping unit 112 includes a moving platen 116, with thefixed and moving platens 114, 116 being interconnected by four tie bars118. The clamping pressure is generated by hydraulic cylinders 120through intervention of the tie bars 118. A swivel plate 122 ispositioned between the platens 114, 116 for attachment of molding tools124. The molding tools 124 interact with complementary molding tools126, 127 in a manner as described with reference to the injectionmolding machine of FIGS. 1-3.

In the embodiment of the injection molding machine of FIGS. 4-7, thesecond plasticizing unit 132 is secured to a mounting 142 which isconnected to a frame 140. The frame 140 extends essentially over theclamping unit 112 and is supported on one end by two uprights 143 behindthe moving platen 116 and on the other end by the fixed platen 114.Mounted to the topside of the frame 140 are two guide rails 141 whichextend in spaced-apart parallel relationship longitudinally in thedirection of the clamping unit 112. The mounting 142 is guided along theguide rails 141 for linear movement.

The second plasticizing unit 132 includes a plasticizing cylinder 134and two hydraulic cylinders 133 for realizing up and down movements ofthe plasticizing cylinder 134.

Depending on the dimension of the molding tools 124, 126, 127, theplasticizing unit 132 can be positioned precisely and accurately inrelation to an injection opening by the movable mounting 142. Thecapability to move up and down enables the plasticizing unit 132 to movedownwards, when the molding tool is closed, for injection of melt intothe cavity. The plasticizing unit 132 moves up again, before the moldingtool is opened.

The injection molding machine of FIGS. 4-7 has overall also a relativelysmall footprint and requires thus little space.

While the invention has been illustrated and described in connectionwith currently preferred embodiments shown and described in detail, itis not intended to be limited to the details shown since variousmodifications and structural changes may be made without departing inany way from the spirit of the present invention. The embodiments werechosen and described in order to best explain the principles of theinvention and practical application to thereby enable a person skilledin the art to best utilize the invention and various embodiments withvarious modifications as are suited to the particular use contemplated.

1. A horizontal injection molding machine, comprising: a machine bed; aclamping unit defining a horizontal axis and mounted on the machine bed,said clamping unit including a first platen, a second platen, and anintermediate plate disposed between the first and second platens, thefirst and second platens and the intermediate plate including moldingtools disposed in horizontal alignment and providing at least twodifferent cavities; a first plasticizing unit charging plastic materialinto one of the cavities; a second plasticizing unit charging plasticmaterial into the other one of the cavities; a mounting securing thesecond plasticizing unit in a substantially vertical orientation inrelation to the horizontal axis in side-by-side relationship to themounting; and a stationary frame disposed above the clamping unit andhaving one end supported directly on the machine bed and anotherend-distal portion placed upon a fixed one of the first and secondplatens, said mounting being secured atop the frame.
 2. The injectionmolding machine of claim 1, wherein the frame envelopes at least part ofthe clamping unit.
 3. The injection molding machine of claim 1, whereinthe mounting is arranged on the frame for linear movement in opening andclosing directions of the clamping unit.
 4. The injection moldingmachine of claim 3, wherein the frame supports two guide rails extendingin parallel relationship in a longitudinal direction of the clampingunit for guiding the mounting.